A gas turbine engine typically includes an inlet, a compressor, a combustor, a turbine, and an exhaust duct. The compressor draws in ambient air and increases its temperature and pressure. Fuel is added to the compressed air in the combustor, where it is burned to raise gas temperature thereby imparting energy to the gas stream. To increase gas turbine engine efficiency, it is desirable to increase the temperature of the gas entering the turbine stages. This requires the first stage turbine engine components (e.g. vanes and blades) to be able to withstand the thermal and oxidation conditions of the high temperature combustion gas during the course of operation.
To protect turbine engine components from the extreme conditions, such components typically include metallic coatings (e.g. aluminides and MCrAlY coatings) that provide oxidation and/or corrosion resistance. The metallic coatings may also function as bond coats to adhere thermal barrier coatings to the substrates of the turbine engine components. Existing bond coats are applied to turbine engine components using a variety of deposition techniques (e.g. plasma spraying, cathodic arc plasma deposition, pack cementation, and chemical vapor deposition techniques). The ceramic thermal barrier coatings are then applied over the bond coats to thermally insulate the turbine engine component from the extreme operating conditions. Each bond coat deposition technique offers challenges that, unless resolved, can lead to quality, throughput, and expense issues for the finished product.